As regards M+, the ninth highest IO DPS Warrior in the world atm is Arms, and they’re not some huge gap behind 1st place. Its ceiling is still plenty high.
But yes, the community will mostly expect you to play Fury, all the while forgetting that Arms has the superior two-target pressure, will typically have the greater burst across 20-25 second fights, and comes with a 6s tank-immunity every 90 seconds.
Overall, Fury is the more steady and reliable spec, but Arms’ weaknesses in M+ are more a matter of synchronization than on-paper tuning.
In raid… yeah, Arms is just undertuned. (Huntsman Altimor, for instance, should be an ideal fight for Arms, and yet its performance there is only middling.)